biostudies-literatureYang KZhejiang Natural Science FoundationNational Natural Science Foundation of China6699https://www.ebi.ac.uk/biostudies/studies/S-EPMC10537072biostudies-literatureUnknown28(18)Catechols have important applications in the pharmaceutical, food, cosmetic, and functional material industries. 4-hydroxyphenylacetate-3-hydroxylase (4HPA3H), a two-component enzyme system comprising HpaB (monooxygenase) and HpaC (FAD oxidoreductase), demonstrates significant potential for catechol production because it can be easily expressed, is highly active, and exhibits <i>ortho</i>-hydroxylation activity toward a broad spectrum of phenol substrates. HpaB determines the <i>ortho</i>-hydroxylation efficiency and substrate spectrum of the enzyme; therefore, studying its structure-activity relationship, improving its properties, and developing a robust HpaB-conducting system are of significance and value; indeed, considerable efforts have been made in these areas in recent decades. HereMolecules (Basel, Switzerland)Advances in 4-Hydroxyphenylacetate-3-hydroxylase Monooxygenase.PMC10537072LY23B0600013207126832071268, 3197137231971372LY21B06000332371542LY21B060003, LY23B060001Mei LHu SYang KHuang JMei JZhao WLv CZhang QfalseAdvances in 4-Hydroxyphenylacetate-3-hydroxylase Monooxygenase.Catechols have important applications in the pharmaceutical, food, cosmetic, and functional material industries. 4-hydroxyphenylacetate-3-hydroxylase (4HPA3H), a two-component enzyme system comprising HpaB (monooxygenase) and HpaC (FAD oxidoreductase), demonstrates significant potential for catechol production because it can be easily expressed, is highly active, and exhibits <i>ortho</i>-hydroxylation activity toward a broad spectrum of phenol substrates. HpaB determines the <i>ortho</i>-hydroxylation efficiency and substrate spectrum of the enzyme; therefore, studying its structure-activity relationship, improving its properties, and developing a robust HpaB-conducting system are of significance and value; indeed, considerable efforts have been made in these areas in recent decades. Here2023-01-01T00:00:00Z2023 Sep2026-04-08T14:31:43.641Z2025-02-19T00:00:46.168ZS-EPMC105370723776447510.3390/molecules28186699